feat(04-02): add script download API endpoints and router registration

- imptune/api/scripts.py: GET /printers/{id}/scripts/{install,uninstall,detect}
- 404 for missing printer, 422 for missing driver/INF/driver_desc
- Content-Disposition attachment header on all responses
- imptune/main.py: register scripts.router
- 5 integration tests covering all endpoint cases (200/404/422)

tests/test_script_generator.py

@@ -3,6 +3,30 @@ import pytest
 from imptune.generators.script_generator import render_detect, render_install, render_uninstall
 
 
+def _create_test_driver_and_printer():
+    """Helper: create a Driver + Printer for integration tests."""
+    from imptune.db.models import Driver, Printer
+
+    driver = Driver.create(
+        sha256="abc123",
+        original_filename="test.zip",
+        size_bytes=100,
+        driver_desc='["Test Driver"]',
+        inf_filename="test.inf",
+    )
+    printer = Printer.create(
+        name="Test Printer",
+        ip_address="10.0.0.1",
+        port_name="IP_10.0.0.1",
+        driver=driver,
+        duplex_mode="LongEdge",
+        color_mode=True,
+        paper_size="A4",
+        collate=True,
+    )
+    return driver, printer
+
+
 SAMPLE_ARGS = dict(
     printer_name="HP LaserJet 4000",
     ip_address="192.168.1.10",
@@ -118,3 +142,56 @@ def test_render_detect():
     assert "Write-Output" in result
     assert "exit 0" in result
     assert "exit 1" in result
+
+
+# ---------------------------------------------------------------------------
+# Integration tests — script API endpoints
+# ---------------------------------------------------------------------------
+
+
+def test_install_endpoint(client):
+    """GET /printers/{id}/scripts/install returns 200 with pnputil in content."""
+    _driver, printer = _create_test_driver_and_printer()
+    response = client.get(f"/printers/{printer.id}/scripts/install")
+    assert response.status_code == 200
+    assert "pnputil" in response.text
+
+
+def test_uninstall_endpoint(client):
+    """GET /printers/{id}/scripts/uninstall returns 200 with Remove-Printer in content."""
+    _driver, printer = _create_test_driver_and_printer()
+    response = client.get(f"/printers/{printer.id}/scripts/uninstall")
+    assert response.status_code == 200
+    assert "Remove-Printer" in response.text
+
+
+def test_detect_endpoint(client):
+    """GET /printers/{id}/scripts/detect returns 200 with Write-Output in content."""
+    _driver, printer = _create_test_driver_and_printer()
+    response = client.get(f"/printers/{printer.id}/scripts/detect")
+    assert response.status_code == 200
+    assert "Write-Output" in response.text
+
+
+def test_script_endpoint_missing_printer(client):
+    """GET /printers/{id}/scripts/install returns 404 for nonexistent printer."""
+    response = client.get("/printers/9999/scripts/install")
+    assert response.status_code == 404
+
+
+def test_script_endpoint_no_driver(client):
+    """GET /printers/{id}/scripts/install returns 422 when no driver assigned."""
+    from imptune.db.models import Printer
+
+    printer = Printer.create(
+        name="No Driver Printer",
+        ip_address="10.0.0.2",
+        port_name="IP_10.0.0.2",
+        driver=None,
+        duplex_mode="OneSided",
+        color_mode=True,
+        paper_size="A4",
+        collate=True,
+    )
+    response = client.get(f"/printers/{printer.id}/scripts/install")
+    assert response.status_code == 422